Often overclocking in search if higher performance of computer hardware require increasing operation voltages. In most extreme cases, onboard power regulators is unable to cope with much higher currents and voltages, and as a solution external power modules are used. One of these modules is EVGAEPOWERCLASSIFIED device. It is available for technology enthusiasts with limited DOA warranty.

Basically module is a multi-phase synchronous buck DC-DC convertor which takes +12V input voltage and regulates it down to 0.6-2.0V, providing over 400 Amps of current.
Since different applications may need different output voltages, in this article we will cover four possible ways to adjust voltage on the fly, at any time device is operating.

All three connectors must be used, as different phases taking power from separate connectors. Main power stage train using 14 phases, using IRF DirectFETs. Output voltage provided on exposed PCB copper edge on component side,
and ground return is exposed on bottom side of board. Good ventilation is highly recommended for optimal performance with higher power levels.

Disclaimer

Before we dig deep into details, here’s necessary part to notice:

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Using onboard DIP-switch to control EVGAEPOWERCLASSIFIED output voltage (up to 1.65 V)

Output voltage

DIP switch position

1

2

3

4

894 mV

OFF

OFF

OFF

OFF

950 mV

OFF

OFF

OFF

ON

1020 mV

OFF

OFF

ON

OFF

1052 mV

OFF

OFF

ON

ON

1105 mV

OFF

ON

OFF

OFF

1157 mV

OFF

ON

OFF

ON

1210 mV

OFF

ON

ON

OFF

1262 mV

OFF

ON

ON

ON

1315 mV

ON

OFF

OFF

OFF

1366 mV

ON

OFF

OFF

ON

1420 mV

ON

OFF

ON

OFF

1472 mV

ON

OFF

ON

ON

1525 mV

ON

ON

OFF

OFF

1577 mV

ON

ON

OFF

ON

1630 mV

ON

ON

ON

OFF

1682 mV

ON

ON

ON

ON

Adjusting voltage is possible with toggling 4-position switch SW1. It’s located near top right corner of EPOWER board, just nearFAN and EVBOT interface connector. Switch can be adjusted any time, unless voltage setting is overridden by digital setting (from I2C command).

Using variable resistor to control EVGAEPOWERCLASSIFIED output voltage

If you need finer steps than DIP-switch method provide, or require voltage output higher than 1.68V, you can add trim pot resistor to offset voltage setting.
To do so you will need:

First remove solder mask in bottom right corner, like shown on photo below. This will be our ground connection spot.
Then measure resistor middle terminal and adjust resistor for maximum resistance. In our case it was 984 ohm.

Now connect middle terminal with small wire to capacitor left side, like shown.

Check all connections and make sure nothing else got shorted.

Original stock condition (shown on photo at left side) have 0.9V as default settings (all VID switches off) and resistance to ground on capacitor terminal reads near 100 ohms. To properly measure resistance, output is required to be shorted
or connected to low-resistance load, as this is part of feedback network. In our case 0.1 ohm resistor was used as a load.

Added trim resistor reduced resistance to 74.5 ohm, which raised output voltage ~300mV, resulting 1.200 VDC. Pay attention as you still can set voltages by VID switch or digitally, but now your output voltage will be with positive offset 300mV. So if you set 1.630V by switch, you will get now 1.930V or about that.

Using EVGAEVBOT to control EVGAEPOWERCLASSIFIED output voltage (up to 1.85 V)

If you happen to have EVBOT controller, you can use it to adjust output voltage by simply connecting to 5-pin digital port at EPOWER. You will need EVGAEPOWER V25 firmware flashed to your EVBOT.

Gamer VID it is, that’s the function which we will use.
Due to safety reasons, we will cap maximum output voltage to 2V, as most modern VGA cards have capacitors on Vcore rated only up to 2V.
Solid capacitors may have nasty explosions and fire if overvoltage happens.

To get started connect your Raspberry Pi I2C interface to EVGA EPower

EVBOT Pinout and connection map is shown in table below:

Raspberry Pi signal name

Raspberry Pi Pin

EVBOT Pin

Ground

Pin 9 on header P1

Pin 6 on header J3501

I2C Data, SDA

Pin 3 on header P1

Pin 5 on header J3501

I2C Clock, SCL

Pin 5 on header P1

Pin 3 on header J3501

EVBOT Pinout is next (looking at connector’s face):

Pin 1

Pin 3 SCL

Pin 4

Pin 5 SDA

Pin 6 GND

Now you can power everything on, and connect to Raspberry Pi terminal.
Download next tool and put into Pi’s disk storage.

If that happens, check that I2C bus is accessible, and all connection between Pi and EPOWER is correct.
Using i2c-tools i2cdetect with proper connection should give you present devices on address 0×0C and 0×46.

Here voltages in 100mV steps were entered, and actual readout values for input, output voltages and temperature was reported.
If user enter zero value into desired voltage request – tool will switch to monitoring mode, which will report current settings in infinite loop.
This could be handy to see if some protection, like OCP/OVP shutdowns output voltage during benching session.

Hope this will help to get higher overclocks and records out of your hardware.